Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
  • B60T11/00—Transmitting braking action from initiating means to ultimate brake actuator without power assistance or drive or where such assistance or drive is irrelevant
  • B60T11/10—Transmitting braking action from initiating means to ultimate brake actuator without power assistance or drive or where such assistance or drive is irrelevant transmitting by fluid means, e.g. hydraulic
  • B60T11/16—Master control, e.g. master cylinders
  • B60T11/18—Connection thereof to initiating means
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
  • B60T13/00—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems
  • B60T13/74—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems with electrical assistance or drive
  • B60T13/745—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems with electrical assistance or drive acting on a hydraulic system, e.g. a master cylinder
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16H—GEARING
  • F16H25/00—Gearings comprising primarily only cams, cam-followers and screw-and-nut mechanisms
  • F16H25/18—Gearings comprising primarily only cams, cam-followers and screw-and-nut mechanisms for conveying or interconverting oscillating or reciprocating motions
  • F16H25/20—Screw mechanisms
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16H—GEARING
  • F16H25/00—Gearings comprising primarily only cams, cam-followers and screw-and-nut mechanisms
  • F16H25/18—Gearings comprising primarily only cams, cam-followers and screw-and-nut mechanisms for conveying or interconverting oscillating or reciprocating motions
  • F16H25/20—Screw mechanisms
  • F16H25/2018—Screw mechanisms with both screw and nut being driven, i.e. screw and nut are both rotating
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
  • B60T13/00—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems
  • B60T13/74—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems with electrical assistance or drive
  • B60T13/746—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems with electrical assistance or drive and mechanical transmission of the braking action
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16H—GEARING
  • F16H25/00—Gearings comprising primarily only cams, cam-followers and screw-and-nut mechanisms
  • F16H25/18—Gearings comprising primarily only cams, cam-followers and screw-and-nut mechanisms for conveying or interconverting oscillating or reciprocating motions
  • F16H25/20—Screw mechanisms
  • F16H2025/2046—Screw mechanisms with gears arranged perpendicular to screw shaft axis, e.g. helical gears engaging tangentially the screw shaft
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16H—GEARING
  • F16H25/00—Gearings comprising primarily only cams, cam-followers and screw-and-nut mechanisms
  • F16H25/18—Gearings comprising primarily only cams, cam-followers and screw-and-nut mechanisms for conveying or interconverting oscillating or reciprocating motions
  • F16H25/20—Screw mechanisms
  • F16H2025/2062—Arrangements for driving the actuator
  • F16H2025/2081—Parallel arrangement of drive motor to screw axis

Definitions

• the invention relates to a brake booster for a master cylinder of a motor vehicle, comprising a drive motor which is connected by a transmission with a pressure piston for the master cylinder or connectable, wherein the transmission comprises a rotatable spindle nut with an internal thread and a rotationally fixed spindle rod with an external thread, wherein the Thread engage with each other to convert a rotational movement of the drive motor in a translational movement of the pressure piston, and wherein the
• Gearing of a drive wheel of the transmission is. Furthermore, the invention relates to a braking device for a motor vehicle, with one of a driver
• the gearbox has a section that as
• the spindle gear is adapted to a rotational movement of the drive motor in a translational movement of the spindle rod for actuating the To convert pressure piston.
• the spindle gear has for this purpose a spindle nut with an internal thread and a spindle rod with an external thread, wherein the two threads are in engagement with each other to the
• spindle gear with trapezoidal threads, so that both the internal thread and the external thread are formed as a trapezoidal thread and engage each other accordingly.
• spindle nut For driving the spindle nut, it is also known to provide the spindle nut with an external toothing, which meshes with the toothing of a drive wheel of the transmission in order to transmit the torque provided by the drive motor to the spindle nut.
• the drive wheel can be arranged for example next to the spindle nut such that the axes of rotation of spindle nut and drive wheel are aligned parallel to each other.
• the brake booster according to the invention has the advantage over the known embodiments that an emergency operation is ensured, which allows actuation of the master cylinder by the driver independently of a control of the drive motor.
• the driver can actuate the brake pedal and the pressure piston for actuating the
• the invention thus allows an advantageous integration of the brake booster in an existing
• the brake booster according to the invention is characterized in that the spindle nut is axially displaceable to the drive wheel. Due to the axial displaceability, the spindle nut can be axially moved or displaced translationally with the spindle rod. When the user presses the
• Brake pedal applies a sufficiently high force, it can thus ensure that the spindle rod moves and thereby the spindle nut is taken and axially displaced to the drive wheel.
• the axial displacement of the spindle nut is thus ensured that the spindle thread is not damaged when the user exerts a correspondingly high braking force on the brake pedal to move the plunger.
• the outer teeth of the spindle nut on a sleeve-shaped portion of the spindle nut extends further than the toothing of the drive wheel, so that external teeth and teeth are independent of an axial displacement of the spindle nut for rotational driving into engagement.
• the spindle nut and the drive wheel are thus still interlocked even when the spindle nut has been moved axially to a starting position. This makes it possible even with already shifted spindle nut that by controlling the
• Drive motor which is designed in particular as an electric motor
• the driver is supported by an electric motor generated torque acting on the spindle nut of the drive wheel.
• This allows the driver to be supported at all times by the brake booster in operation. This makes it possible, for example, that when a user operates the brake pedal faster than the drive motor can react, although not equal to the beginning of the operation but in the course within a very short time an additional braking torque can generate, for example, even then if the spindle rod has already been moved axially for a while.
• the external toothing is formed as an axial toothing.
• the spindle nut is axially displaceable at any time, for example, because the friction torque of the transmission and the drive motor can not act inhibiting on the displacement of the spindle nut.
• the spline is also inexpensive to produce.
• the gear mechanism formed by the external teeth and the toothing is expediently designed such that the teeth of the respective
• Teeth are shaped and dimensioned depending on their material. Thus, it is provided in particular that teeth which are made of a less solid material, have a larger tooth width, than teeth which are made of a stronger material.
• the geometry of the toothing or the transmission is expediently chosen such that among all Ambient conditions sufficient coverage of the teeth and thus a secure torque transmission is guaranteed.
• the drive wheel is designed as a drive ring gear and the teeth as internal teeth of the drive ring gear.
• the drive ring gear is arranged coaxially to the spindle nut and the spindle nut is passed through the drive ring gear.
• the torque provided by the drive ring gear is uniformly transmitted to the spindle nut.
• Internal toothing is also preferably achieved that Antriebshohlrad and spindle nut are automatically centered to each other.
• the tooth flanks of the teeth are each aligned obliquely with respect to a radial extent, so that the teeth have a conical cross-section.
• the spindle nut has an axial stop for the drive ring gear.
• the spindle nut is maximally axially displaceable until the axial stop strikes against the drive ring gear.
• the displaceability of the spindle nut is limited in at least one axial direction. In particular, this can be achieved by reliably preventing the outer toothing from disengaging from the toothing during an axial displacement or from disengaging it.
• the axial stop also defines a preferred starting position of the spindle nut with respect to the drive ring gear.
• the axial stop is formed at least partially perpendicular to the axial extension of the spindle nut.
• the axial stop forms a perpendicular to the path of movement of the spindle nut aligned stop, which thus far meets flat or perpendicular to the drive ring gear. As a result, particularly large axial forces can be transmitted.
• the axial stop inclined at least in sections Axial extension of the spindle sleeve is aligned.
• Section of the axial stop is achieved that in addition to an axial force and radial forces are transmitted from the spindle nut to the drive ring gear, which in particular an advantageous centering of the spindle nut is achieved to drive ring gear when the axial stop against the
• the axial stop is conical, so that it has an over the entire circumference extending and inclined to the axial extension of the spindle sleeve aligned stop surface. Due to the conical design is a particularly advantageous automatic centering of
• the drive ring gear on a complementary to the axial stop formed stop. This ensures an advantageous fit and advantageous interaction between the spindle nut and the drive ring gear.
• the axial stop is partially or fully conical, resulting from the complementary design of the stop of the drive ring gear advantageous centering.
• the external toothing of the spindle nut extends into the axial stop.
• the axial stop has a portion of the toothing or external toothing, whereby the displacement of the spindle nut is maximized and high, especially in the region of the axial stop
• the braking device according to the invention with the features of claim 12 is characterized by the brake booster according to the invention. This results in the already mentioned advantages. Further advantages and preferred features emerge in particular from the previously described and from the claims.
• the pressure piston forms the spindle rod or is acted upon in direct extension of the spindle rod of this mechanically.
• the pressure piston in particular of the master cylinder is an integral part of the brake booster, creating a particularly compact
• Embodiment of the braking device is provided.
• Figure 1 is a brake booster in a perspective
• Figure 2 is a cross-sectional view through a transmission of
• FIG. 3 is a simplified longitudinal sectional view of the transmission
• Figures 4A and 4B design variants of an axial stop a
• Figure 5 is a perspective partial view of the transmission.
• FIG. 1 shows, in a simplified illustration, a brake booster for a master brake cylinder of a motor vehicle (not illustrated here).
• the brake booster 1 has a simplified representation here
• the Drive motor 2 which is designed as an electric motor and is operatively connected by a transmission 3 with a pressure piston.
• the pressure piston is present only partially and shown in a longitudinal section.
• the pressure piston is designed as a hollow rod which has an external thread 5.
• the pressure piston is single-ended mechanically connected to the master cylinder and the other end with a brake pedal of the brake booster 1 having motor vehicle.
• the pressure piston is formed axially displaceable to exert a force on the master cylinder to actuate the brake pedal to its operation.
• the pressure piston 4 forms by the external thread 5 a spindle rod on which a spindle nut 6 is rotatably arranged.
• the spindle nut 6 has in sections an internal thread 7, which is in engagement with the external thread 5.
• the external thread 5 and the internal thread 7 are each formed as a trapezoidal thread.
• the external thread 5 extends axially over a more than twice as large portion as the internal thread 7. If the spindle nut 6 is set in a rotational movement, as indicated by an arrow 8, this leads to an axial displacement of the spindle rod by the intermeshing trapezoidal thread forming pressure piston 4, as shown by an arrow 9.
• the spindle nut 6 also has an outer toothing 10, with a plurality of axially extending teeth. Furthermore, the spindle nut 6 at one end to an axial stop 11, which is a cone-shaped
• the transmission 3 furthermore has a drive ring gear 12, which has an internal toothing 13 which is in engagement with the external toothing 10.
• the spindle nut 6 is axially displaceable to the drive ring gear 12. Furthermore, the drive ring gear 12 has an outer toothing, with which the drive ring gear 12 is operatively connected to an intermediate gear 15 having a gear stage and with a
• the spindle nut 6 is pushed back with the axial stop 11 against the Antriebshohlrad 12, so that the axial stop 11 rests against the drive ring gear 12 and a further movement is impossible.
• the spring element By the spring element, the transmission 3 is biased in the direction of an initial state.
• FIG. 2 shows a cross section through the drive ring gear 12. It can be seen here that teeth 17 of the external thread 10 and the teeth 18 of the internal thread 13 meshing therewith each have inclined tooth flanks, so that the teeth 17, 18 each have a trapezoidal cross section. As a result, the meshing teeth 17 and 18 act centering for the spindle nut 6 and the drive ring gear 12. By choosing the contour of the teeth 17, 18 ensures that the drive ring gear 12 and spindle nut 6 are automatically centered to each other. Especially if that
• Drive ring gear 12 is driven by the drive motor 2 to a
• a radial centering of the drive ring gear 12 to the spindle nut 6 is performed due to the inclined tooth flanks, whereby the drive ring gear 12 and spindle nut 6 are automatically aligned optimally to each other.
• the teeth 18 of the Antriebshohlrads 12 extend less far axially, as the teeth 17 of the Antriebshohlrads 12, so that the spindle nut 6 corresponding to the longitudinal extent of the Teeth 17 is axially displaceable with respect to the Antriebshohlrads 12 without the rotational drive of the toothing is lost.
• the tooth width of the teeth 17 and 18 is advantageously chosen as a function of their material strength. This material properties of the
• the spindle nut 6 and the Antriebshohlrads 12 set in relation to each other and the tooth widths selected in accordance with this ratio.
• the spindle nut 6 is made of a less solid material compared to the Antriebshohlrad 12, and thus also has a comparatively larger tooth width B.
• the geometry of the toothing, ie of internal teeth 13 and external teeth 10, is selected in this case in that, under all expected ambient conditions, such as, in particular, temperature or humidity, sufficient overlap of the teeth 17 and 18 for rotary driving is ensured.
• FIGS. 4A and 4B show different embodiments of the axial stop 11 of the spindle nut 6 in each case in a longitudinal sectional view of the transmission 1.
• Figure 4A shows the axial stop 11 according to a first
• Axial extension of the spindle nut 6 extends radially outward, so that it forms a flat or vertical stop surface 19.
• Drive ring gear 12 is formed complementary to the axial stop 11, so that it also has a stop 20 which forms a stop surface 19 complementary to the stop surface.
• a stop 20 which forms a stop surface 19 complementary to the stop surface.
• An arrow in FIGS. 4A and 4B shows, by way of example, the axial load on the
• Figure 4B shows a further embodiment, as shown in Figure 1, in which the axial stop 11 is conical and thus extending over the entire circumference inclined to the axial extent of
• Stop 20 of the drive ring gear 12 cooperates.
• the inclined abutment surface 19 ensures that the axial load is supported both axially and radially. In particular, by the radial support thereby takes place an advantageous centering of the spindle nut 6 to Antriebshohlrad 12. Die
• Distribution of the force not only relieves the interface, but also reduces the radial deformation of the spindle nut 6, which is generated by the force distribution from the trapezoidal thread or from engagement with the spindle rod 4.
• the spindle nut 6 is thus driven by the drive motor 2 by means of the transmission 3 in order to displace the spindle rod 4 for actuating the pressure piston, the spindle nut 6 is advantageously supported on the stop 20 of the drive ring gear 12 by the axial stop 11.
• FIG. 5 shows a perspective partial representation of the transmission 1 in the region of the drive ring gear 12 according to a further exemplary embodiment.
• the external toothing 10 of the spindle nut 6 extends into the axial stop 11.
• the axial stop 11 is formed according to the embodiment of Figure 4B, with a conical abutment surface 19. Due to the fact that the
• the stop surface 19 is distributed evenly distributed over the circumference, so that the axial stop is formed by a plurality of inclined to the axial extension of the spindle sleeve 6 stop surfaces 19.
• the teeth 18 of the Internal teeth 13 of the drive ring gear 12 thus overlap partially in the axial stop 11 when the spindle nut 6 is brought up to the drive ring gear 12, so that the stop surfaces 19 meet correspondingly formed stop counter surfaces of the stop 20 of the drive ring gear 12.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Transportation (AREA)
• Braking Systems And Boosters (AREA)
• Transmission Devices (AREA)

Priority Applications (7)

Applications Claiming Priority (2)

Publications (1)

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Citations (4)

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• 2015
  • 2015-09-14 DE DE102015217548.0A patent/DE102015217548A1/de active Pending
• 2016
  • 2016-07-13 PL PL16738762T patent/PL3350039T3/pl unknown
  • 2016-07-13 WO PCT/EP2016/066623 patent/WO2017045796A1/de active Application Filing
  • 2016-07-13 CN CN201680053112.0A patent/CN107949510B/zh active Active
  • 2016-07-13 KR KR1020187010120A patent/KR102573826B1/ko active IP Right Grant
  • 2016-07-13 US US15/759,266 patent/US10604133B2/en active Active
  • 2016-07-13 EP EP16738762.0A patent/EP3350039B1/de active Active
  • 2016-07-13 JP JP2018509921A patent/JP6641458B2/ja active Active
  • 2016-07-13 ES ES16738762T patent/ES2763803T3/es active Active

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